Combination chemotherapy for metastatic carcinoma of the breast utilizing combinations of active single agents can produce high response rates with improvement in the patients' survival. There are many active combinations with response rates which vary from 40-80%. There is a wide variation in reported response rates, but there are few prospective comparative trials of the various treatment regimens, and few studies which stratify for the prognostic variables. The current study randomly compares 3 active combination chemotherapy regimens for response rates, duration, and survival. In addition, the current study evaluates the effect of MER immunotherapy upon response rate, duration, survival, or its effect on drug toxicities. Since carcinoma of the breast is a very heterogenous disease and there are multiple treatment arms in this protocol, a large cooperative group effort is necessary to stratify for all the variables and the treatment arms. The protocol was activated October 11, 1976, and 219 patients have been entered onto protocol. Preliminary evaluations of this study reveal no differences in any of the six treatment arms. Stable survival data are not available at the present time.